Prepare and grease cookie sheet. Using a heavy saucepan and over medium heat, boil water, syrup, sugar, and salt. Stir until sugar is dissolved. Add peanut. When it begins to thicken, test; drop a little in cold water. When it turns into hard and brittle thead, remove from heat and immediately stir in baking soda and butter. Spread at once on the greased cookie sheet. Use 2 forks to spread and stretch. Swift action is needed in this stage or your candy would harden without being spread. When cool, snap candy into small pieces by hand. Store in bottle with a tight cover.